India's annual infrastructure output growth slowed to a three-month low of 2.5 percent in April, mainly dragged down by a slowdown in refinery output and a contraction in coal production, government data showed on Wednesday.

The output grew a revised 5.3 percent year-on-year in March.

Annual growth in refinery production slowed down to 0.2 percent last month from 2.0 percent in March. Coal production fell 3.8 percent on year from a 10.8 percent growth in March.